[unreadable] The University of Pennsylvania (UPenn) School of Medicine is one of the nations premier biomedical research institutions. Funding from the National Institutes of Health (NIH) alone totaled $347 million in FY2002, which ranks second among all academic medical centers. Growth in UPenn's sponsored research was nearly 200 percent during the past decade. As much of this work is dependent upon rodent systems and models, the murine colony expanded at nearly 20 percent annually during this time. Thus despite aggressive facility expansion, current animal housing capacity is nearly saturated, and funded or planned research activities are in jeopardy. In view of these facts, funds are requested to build a state-of-the-art rodent barrier facility within a funded new research building to be jointly occupied by faculty from the School of Medicine and the School of Veterinary Medicine. This rodent barrier facility will have a capacity of approximately 10,000 small mouse cages. The thematic scope of this project will be to support three areas of active research that receive significant NIH funding. They are Stem Cell Biology, Infectious Disease and Bioterrorism, and Genetics. A new rodent barrier facility to support these themes of research will consolidate this research for greater collaborative work among investigators and increased resource efficiencies while significantly decreasing overcrowded conditions experienced in other rodent facilities on campus. The School of Medicine is committed to maintaining full accreditation with AAALAC International. This facility will meet AAALAC standards, improve the quality and quantity of rodent housing, and more adequately meet the needs of NIH-funded research. [unreadable] [unreadable]